Follow the steps in this repair guide and video to replace the gear and sprocket assembly in craftsman chamberlain and liftmaster chain drive garage door openers.
How to replace drive gear on craftsman garage door opener.
The worm gear which attaches to the motor shaft meshes with the drive gear to spin the sprocket and drive the chain to open and close the garage door.
This was a craftsman model 139 53976srt.
Replace a broken gear and sprocket assembly with the manufacturer approved replacement part.
This is a video on how to change the gear sprockets in a craftsman garage door opener.
If the gears break or strip the door won t move.